brozek/SLOTH
Archived
1
0
Fork 0
Code Activity

Cleaned up error checking code

Browse source
This commit is contained in:
Brandon Rozek 2018-09-18 23:18:20 -04:00
parent fbfaf0ddb8
commit 61301aaa97
1 changed files with 47 additions and 52 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

99
src/parser.y
View file

@ -330,6 +330,11 @@ void delete_environment(struct Environment* env) {
free(env);
}
void check_num_nodes(struct Node* node, int num_children, char* error) {
if (node && node->num_children != num_children) {
fprintf(stderr, "%s%s%s", "Error, ", error, "\n");
}
}
double eval_expression(struct Node* node, struct Environment* env) {
/* base case */
@ -337,98 +342,88 @@ double eval_expression(struct Node* node, struct Environment* env) {
fprintf(stderr, "Error: No tree structure to evaluate\n");
return 0;
}
int nodeNotValid = !(
node->type == IDENTIFIER ||
node->type == VALUE ||
node->type == INPUT ||
node->type == PLUS ||
node->type == MINUS ||
node->type == DIVIDE ||
node->type == TIMES ||
node->type == LESS ||
node->type == GREATER ||
node->type == LESSEQ ||
node->type == GREATEREQ ||
node->type == EQUALS ||
node->type == NEQUALS ||
node->type == AND ||
node->type == OR ||
node->type == NOT
);
if (nodeNotValid) {
fprintf(stderr,"Error, %d not a valid expression type.\n", node->type);
return 0;
}
// Needed if we are going to take input from the user
double temp;
struct Variable* var = NULL;
// Evaluate subexpressions if existent
double val1, val2, val3;
if (node->num_children > 0) {
val1 = eval_expression(node->children[0], env);
if (node->num_children > 1) {
val2 = eval_expression(node->children[1], env);
if (node->num_children > 2) {
val3 = eval_expression(node->children[2], env);
}
}
}
switch(node->type) {
case PLUS:
if (node->num_children != 2) { fprintf(stderr, "Error, cannot add more than two expressions.\n"); }
return eval_expression(node->children[0], env) + eval_expression(node->children[1], env);
check_num_nodes(node, 2, "cannot add more than two expressions.");
return val1 + val2;
break;
//----------
case MINUS:
if (node->num_children != 2) { fprintf(stderr, "Error, cannot subtract more than two expressions.\n"); }
return eval_expression(node->children[0], env) - eval_expression(node->children[1], env);
check_num_nodes(node, 2, "cannot subtract more than two expressions.");
return val1 - val2;
break;
//----------
case DIVIDE:
if (node->num_children != 2) { fprintf(stderr, "Error, cannot divide more than two expressions.\n"); }
return eval_expression(node->children[0], env) / eval_expression(node->children[1], env);
check_num_nodes(node, 2, "cannot divide more than two expressions.");
return val1 / val2;
break;
//----------
case TIMES:
if (node->num_children != 2) { fprintf(stderr, "Error, cannot multiply more than two expressions.\n"); }
return eval_expression(node->children[0], env) * eval_expression(node->children[1], env);
check_num_nodes(node, 2, "cannot multiply more than two expressions.");
return val1 * val2;
break;
//----------
case LESS:
check_num_nodes(node, 2, "cannot compare more than two expressions.");
if (node->num_children != 2) { fprintf(stderr, "Error, cannot compare more than two expressions.\n"); }
return eval_expression(node->children[0], env) < eval_expression(node->children[1], env);
return val1 < val2;
break;
//----------
case GREATER:
if (node->num_children != 2) { fprintf(stderr, "Error, cannot compare more than two expressions.\n"); }
return eval_expression(node->children[0], env) > eval_expression(node->children[1], env);
check_num_nodes(node, 2, "cannot compare more than two expressions.");
return val1 > val2;
break;
//----------
case LESSEQ:
if (node->num_children != 2) { fprintf(stderr, "Error, cannot compare more than two expressions.\n"); }
return eval_expression(node->children[0], env) <= eval_expression(node->children[1], env);
check_num_nodes(node, 2, "cannot compare more than two expressions.");
return val1 <= val2;
break;
//----------
case GREATEREQ:
if (node->num_children != 2) { fprintf(stderr, "Error, cannot compare more than two expressions.\n"); }
return eval_expression(node->children[0], env) >= eval_expression(node->children[1], env);
check_num_nodes(node, 2, "cannot compare more than two expressions.");
return val1 >= val2;
break;
//----------
case EQUALS:
if (node->num_children != 2) { fprintf(stderr, "Error, cannot compare more than two expressions.\n"); }
return eval_expression(node->children[0], env) == eval_expression(node->children[1], env);
check_num_nodes(node, 2, "cannot compare more than two expressions.");
return val1 == val2;
break;
//----------
case NEQUALS:
if (node->num_children != 2) { fprintf(stderr, "Error, cannot compare more than two expressions.\n"); }
return eval_expression(node->children[0], env) != eval_expression(node->children[1], env);
check_num_nodes(node, 2, "cannot compare more than two expressions.");
return val1 != val2;
break;
//----------
case AND:
if (node->num_children != 2) { fprintf(stderr, "Error, cannot perform logical operators on more than two expressions.\n"); }
return eval_expression(node->children[0], env) && eval_expression(node->children[1], env);
check_num_nodes(node, 2, "cannot perform logical operators on more than two expressions.");
return val1 && val2;
break;
//----------
case OR:
if (node->num_children != 2) { fprintf(stderr, "Error, cannot perform logical operators on more than two expressions.\n"); }
return eval_expression(node->children[0], env) || eval_expression(node->children[1], env);
check_num_nodes(node, 2, "cannot perform logical operators on more than two expressions.");
return val1 || val2;
break;
//----------
case NOT:
if (node->num_children != 1) { fprintf(stderr, "Error, cannot negate more than one expressions.\n"); }
return !eval_expression(node->children[0], env);
check_num_nodes(node, 1, "cannot negate more than one expressions.");
return !val1;
break;
//----------
case INPUT:
@ -466,7 +461,7 @@ void eval_statement(struct Node* node, struct Environment* env) {
switch(node->type) {
case ASSIGN:
if (node->num_children != 2) { fprintf(stderr, "Error: Cannot make an assignment without an identifier and a value.\n"); }
check_num_nodes(node, 2, "cannot make an assignment without an identifier and a value.");
add_variable(env,
make_variable(node->children[0]->id,
eval_expression(node->children[1], env)));
@ -482,13 +477,13 @@ void eval_statement(struct Node* node, struct Environment* env) {
}
break;
case WHILE:
if (node->num_children != 2) { fprintf(stderr, "Error: The format of a while statement is while expression statement(s)\n"); }
check_num_nodes(node, 2, "the format of a while statement is: while expression statement(s)");
while (eval_expression(node->children[0], env)) {
eval_statement(node->children[1], env);
}
break;
case PRINT:
if (node->num_children != 1) { fprintf(stderr, "Error: Can only print out one expression at a time.\n"); }
check_num_nodes(node, 1, "can only print out one expression at a time.");
printf("%lf\n", eval_expression(node->children[0], env));
break;
case STATEMENT: // Can have a maximum of two children statement nodes
@ -500,7 +495,7 @@ void eval_statement(struct Node* node, struct Environment* env) {
}
break;
default:
printf("Error, %d not a valid node type.\n", node->type);
printf("Error, %d not a valid statement type.\n", node->type);
return;
}
}